These'll Never Break

When the pressure mounts, the right straps are critical

Feature Article from Hemmings Motor News

After all that work tracking down your new car, or that engine you need to finish your project, after negotiating with the seller, after finding the trailer and time to go get it, why would you trust the $10 set of ratcheting tie-downs that you bought off the back of a truck to keep your new acquisition off the hood of the car behind you?
Your tie-down has three components to take the strain: fittings on the end, webbing and a ratchet. The Web Sling & Tie Down Association (your friendly, neighborhood web-slingers) publishes a set of standards that are universally used by transportation and trucking agencies, including the Army, OSHA and the Federal Motor Carrier Safety Administration. A tie-down that conforms to WSTDA-T-1 has had a proof load test performed, where the complete assembly, including the exact hardware attached to that strap, endured a load of 1½ times the rating (working load limit) without damage. A strap with a working load limit of 5,000 pounds also has a minimum design factor of three, meaning it's been tested to at least 30,000 pounds without breaking. Any strap that meets the standard should have a tag with the WSTDA's strap-and-globe logo, and the relevant information. Many also have the working load limit printed right on the fabric.
After you've gone out and spent $150 for a set of four three-inch by 30 feet, 5,000-pound straps, you'll want to give some thought to their care and use. As with all synthetic fabrics, UV from sunlight breaks down the polyester or nylon used in most webbing, so don't let them bounce around in the bed of your pickup. Sharp corners are an obvious no-no, but a less obvious problem is dirt that accumulates around old cars, with the little ground-up rocks, metal filings and grease. Once it works its way into the fabric of the strap, it starts cutting the fibers one by one, so don't just throw it down in the dirt, and it's worth washing dirty webbing with mild dish detergent to extend its life.
The force you're exerting on your load will vary as a function of the angle of the binding, which means that pulling straight down holds your load with 100 percent of the tension of your tie-down. The shallower your angle--like strapping an engine down in the middle of a wide trailer--the less holding force you have. The Catch-22 is that a sharp angle in the webbing lowers the real working load limit, so use a canvas sheath for padding on any hard corners. If your load has straps over the top of it, remember those won't help much in heavy braking, so hook on to the front and back, as well. Any twists or knots in the strap dramatically lessen its working strength, so when you strap something down, make sure your webbing is as straight as possible. (And would it kill you to check for damage before trusting your life--and ours--to it?)
Lastly, when everything is looking good, don't forget to lock down your ratchets in their fully closed position, ensuring that they can't catch on something and open. A 3,000-pound car travelling at 60 mph will exert something like 350,000-lbs.ft. of force coming to a dead stop...so try not to do that.

This article originally appeared in the March, 2008 issue of Hemmings Motor News.